Fountain-like eruptions on Io

. Voyager 1 discovered plumes of active volcanoes on Jupiterís moon Io when the spacecraft flew by the planet on 4-5 March 1979 (left). A computer simulation of a volcanic eruption on Io shows the fountain-like trajectories of the volcanic plume (rightleft), and Nicholas M. Schneider, Lunar and Planetary Laboratory, Tucson (right).]